/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.tomcat.websocket;

import org.apache.juli.logging.Log;
import org.apache.juli.logging.LogFactory;
import org.apache.tomcat.util.res.StringManager;

import javax.websocket.CloseReason;
import javax.websocket.CloseReason.CloseCodes;
import java.io.EOFException;
import java.io.IOException;
import java.nio.ByteBuffer;
import java.nio.channels.CompletionHandler;

public class WsFrameClient extends WsFrameBase {

	private static final StringManager sm =
			StringManager.getManager(Constants.PACKAGE_NAME);
	private final Log log = LogFactory.getLog(WsFrameClient.class);
	private final AsyncChannelWrapper channel;
	private final CompletionHandler<Integer, Void> handler;
	// Not final as it may need to be re-sized
	private ByteBuffer response;

	public WsFrameClient(ByteBuffer response, AsyncChannelWrapper channel,
	                     WsSession wsSession, Transformation transformation) {
		super(wsSession, transformation);
		this.response = response;
		this.channel = channel;
		this.handler = new WsFrameClientCompletionHandler();
	}

	void startInputProcessing() {
		try {
			processSocketRead();
		} catch (IOException e) {
			close(e);
		}
	}

	private void processSocketRead() throws IOException {

		while (response.hasRemaining()) {
			int remaining = response.remaining();

			int toCopy = Math.min(remaining, inputBuffer.length - writePos);

			// Copy remaining bytes read in HTTP phase to input buffer used by
			// frame processing
			response.get(inputBuffer, writePos, toCopy);
			writePos += toCopy;

			// Process the data we have
			processInputBuffer();
		}
		response.clear();

		// Get some more data
		if (isOpen()) {
			channel.read(response, null, handler);
		}
	}

	private final void close(Throwable t) {
		CloseReason cr;
		if (t instanceof WsIOException) {
			cr = ((WsIOException) t).getCloseReason();
		} else {
			cr = new CloseReason(
					CloseCodes.CLOSED_ABNORMALLY, t.getMessage());
		}

		try {
			wsSession.close(cr);
		} catch (IOException ignore) {
			// Ignore
		}
	}

	@Override
	protected boolean isMasked() {
		// Data is from the server so it is not masked
		return false;
	}

	@Override
	protected Log getLog() {
		return log;
	}

	private class WsFrameClientCompletionHandler
			implements CompletionHandler<Integer, Void> {

		@Override
		public void completed(Integer result, Void attachment) {
			if (result.intValue() == -1) {
				// BZ 57762. A dropped connection will get reported as EOF
				// rather than as an error so handle it here.
				if (isOpen()) {
					// No close frame was received
					close(new EOFException());
				}
				// No data to process
				return;
			}
			response.flip();
			try {
				processSocketRead();
			} catch (IOException e) {
				// Only send a close message on an IOException if the client
				// has not yet received a close control message from the server
				// as the IOException may be in response to the client
				// continuing to send a message after the server sent a close
				// control message.
				if (isOpen()) {
					log.debug(sm.getString("wsFrameClient.ioe", e));
					close(e);
				}
			}
		}

		@Override
		public void failed(Throwable exc, Void attachment) {
			if (exc instanceof ReadBufferOverflowException) {
				// response will be empty if this exception is thrown
				response = ByteBuffer.allocate(
						((ReadBufferOverflowException) exc).getMinBufferSize());
				response.flip();
				try {
					processSocketRead();
				} catch (IOException e) {
					close(e);
				}
			} else {
				close(exc);
			}
		}
	}
}
